Isolation And Identification Of Mycoplasma Gallisepticum And Difference Analysis Of Sequence Of MG 16S/23S RRNA Intergenic Spacer Region And TM-1 Gene

Mycoplasma gallisepticum(MG) is a primary pathogen causing chronic respiratory disease in chicken, which is characterized by coughing, nasal discharge, rattling and air-sacculitis. Usually chickens suffered co-infection with Infectious bronchitis, Newcastle virus or Escherichia, and led to forced-breathing and increased mortality. MG infection is common in flocks in our country, but mortality is low, which mainly led to high unhealthy chicken rate and egg production of layer dropped, feed conversion efficiency reduced and the period of onset to market prolonged, the cost of prevention added. At the same time, it could cause drug residua in poultry products. MG infection may result in economic losses in the poultry industry.77 isolates were got from 162 infected or suspicious infected chickens came from 38 poultry flocks in Hubei and Henan province. On the basis of typical clone shape with frig egg and bacteria recovery test, 77 of mycoplasma isolates were purified from 23 chickens of 10 flocks, and 59 were identified as Mycoplasma gallisepticum. Using antiserum prepared with rabbit anti MG-S6 strain, metabolism inhibition titer was 1:2560 for MG-S6 and was 1:160 for MG-HS. MI titer of 1:80 was to be as the criterion. Up or equal to 1:80 isolate was as MG. In the test, the efficiency of metabolism inhibition was between 1:10 and 1:1280, and the metabolism inhibition of 59 strains was between 1:80 and 1:1280, so the 59 strains was identified mycoplasma gallisepticum, and the result of metabolism inhibition accorded with the result of the test of absorption of red blood cell of chicken.The sequence of MG of 16S/23S rRNA intergenic spacer region were successfully amplified, the length of the amplified fragments was about 890 bp, which is special fragment for mycoplasma gallispticum. After purification, the PCR product was analyzed by the restriction fragment length polymorphism (RFLP) method ,in the research, Rsa I was used to digest the PCR products. The result indicated two different RFLP patterns in the all mycoplasma gallisepticun strains, which was 790/100 type and 550/240/100 type. Difference was obvious in genotype of isolations,...